Free tool · 2026–27 financial year
BAS checklist: what to check before you lodge
Tick through each stage before you lodge, from reconciling to keeping the records. Add the client and period, then print it or download it as a CSV to keep one per client. Every check comes from an ATO page and links to it. No sign-up or email needed.
Quarter 1 (July to September 2026) is due 28 October 2026, or later if you lodge online or through an agent: see BAS due dates 2026–27.
GST accounting
Wages to report?
PAYG instalments?
0 of 34 done
Saved in this browser only. Nothing is sent to ClearABN.
1. Before you start
2. Reconcile
3. Sales and income
4. Purchases and GST credits
Check the quarter’s bills in one go
Upload the quarter’s bills export (with an invoice date column, or add your contacts export) and ClearABN checks each supplier’s ABN and GST registration against the Australian Business Register on each bill’s own date, so GST recorded on a bill from a supplier who wasn’t registered that day is flagged. The first 25 rows are free.
Check your bills5. Wages and PAYG withholding
6. Prepare and check
7. Lodge and pay
8. Keep the records
The check most BAS checklists leave out
Plenty of BAS checklists say to hold a tax invoice before claiming a GST credit but stop short of checking that the supplier was registered for GST. The ATO’s guidance is to make sure your suppliers are registered when you claim, because purchases from an entity not registered for GST have no GST in the price and go at G14 on the calculation worksheet. A supplier can have an active ABN without being registered for GST, and a registration can start or end part way through a quarter.
For one supplier, use the free GST check on an invoice date. For the whole quarter, the bulk check takes a bills export and checks each bill on its own date. Step by step: checking a quarter’s bills before the BAS.
Where each check comes from
- ATO, Step 6: Check (last updated 9 September 2026)
- ATO, BAS and GST tips (last updated 26 June 2025)
- ATO, Instructions for completing your BAS (last updated 14 September 2026)
- ATO, Step 4: Calculating purchases using the calculation worksheet (last updated 9 September 2026)
- ATO, When you can claim a GST credit (last updated 14 September 2026)
- ATO, Due dates for lodging and paying your BAS (last updated 17 September 2026)
- ATO, PAYG withholding on your BAS (last updated 1 May 2025)
- ATO, PAYG instalments: how to complete your activity statement (last updated 9 January 2023)
Read on 19 October 2026. If the ATO changes its guidance, its pages take priority over this list.
Common questions
What should I check before lodging a BAS?
The ATO's Step 6 check list: the GST labels that apply to you are filled in, your calculations are accurate, amounts were transferred correctly from your records, the G1 box shows whether the amount includes GST, and your contact phone number is provided. Then complete any other sections that apply, carry the totals to the summary, work out whether you pay or get a refund, and lodge and pay by the due date.
Do I need a tax invoice to claim a GST credit?
For purchases that cost more than A$82.50 including GST, yes. Your supplier has 28 days to give you one after you ask, and the ATO says to wait until you have it before you claim, even if that's in a later period. For A$82.50 or less, a tax invoice, cash register docket, receipt or invoice will do.
What if a supplier wasn't registered for GST?
A GST credit is only for GST included in the price, and the ATO treats purchases from an entity not registered for GST as purchases without GST in the price. On its calculation worksheet they go at G14 (purchases without GST in the price), which reduces the credit at 1B. The ATO says to make sure your suppliers are registered when you claim GST credits; ABN Lookup shows a business's GST registration, and ClearABN's bulk check looks at each bill's own date.
Do I lodge a BAS if I have nothing to report?
Yes. The ATO says you still need to lodge a nil BAS by the due date, online or through its automated phone service.
Do I round the amounts on my BAS?
Round down to whole dollars and leave the cents out. Don't report negative figures or use symbols such as +, −, ÷ or $, and leave labels that don't apply blank unless the form tells you otherwise.
Can I fix a mistake on a BAS I've already lodged?
The ATO says most GST mistakes, such as a clerical error or purchases counted twice, can be corrected in your current BAS. If you can't correct it there, you'll need to revise the original BAS.
How long do I keep BAS records?
Keep a copy of the BAS and the records used to prepare it, including calculation worksheets, for five years after they were prepared or obtained or the transactions were completed, or the period of review, whichever is later.
Is my checklist saved anywhere?
Only in your own browser, so you can come back to it on the same device. Nothing you type or tick is sent to ClearABN. Use Download as CSV to keep one per client and period, or Start a new client to clear it.
This checklist is general information taken from the ATO’s published guidance, not tax advice. Your own BAS and the ATO’s pages are the final word. If you can’t lodge or pay on time, the ATO says to contact them as soon as possible.
More: BAS calculator · BAS due dates 2026–27 · late BAS penalty calculator · no-ABN withholding (W4) calculator · tax invoice checker · GST calculator · GST registration check · check a supplier list